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Lubricant Test Monitoring System ( LTMS) Quick Deck. Draft 3 March 2, 2012. Quick Deck Explanation. The LTMS Task Force Statistics Task Group is looking at LTMS in preparation for the new categories, GF-6 and PC-11.
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Lubricant Test Monitoring System(LTMS) Quick Deck Draft 3 March 2, 2012
Quick Deck Explanation • The LTMS Task Force Statistics Task Group is looking at LTMS in preparation for the new categories, GF-6 and PC-11. • The next slide proposes goals for LTMS. We seek concurrence or suggested alternatives. • The core of our current approach is presented in the following nine slides. • More extensive descriptions and discussions are available from the task group. We welcome you input and participation. Please contact: • Jim Rutherford,LTMS Task Force Statistics Task Group LeaderTel 510 242 3410jaru@chevron.com LTMS TF Statistics Task Group Leader
LTMS Goals • Assist the industry in leveling the playing field for candidate oil performance testing • Promote reliability, integrity, and efficiency of testing • Encourage on target results • Strive for standardization across test types with guidelines and criteria defined for deviations • Generate appropriate confidence about where a lab or stand is on the performance scale relative to the rest of the industry • Eliminate incentives for inappropriate engineering judgments • Are these the goals for LTMS that everyone can support? LTMS TF Statistics Task Group Leader
Severity Adjustment Entity(Lab or Stand) Difference between reference result and current severity estimate Run another reference With predetermined conditions, run another reference EWMA Reduce calibration period Difference between current severity estimate and target Run another reference Target Apply severity adjustment LTMS TF Statistics Task Group Leader
Reference Entity Formulae For each severity adjustment entity, • Ti = ith test result in appropriate units • Yi = ith standardized test result where target and standard deviation are as currently defined for the reference oil used in the reference test LTMS TF Statistics Task Group Leader
Reference Entity Formulae (continued) For each severity adjustment entity, • Zi = EWMA • ei = prediction error from EWMA LTMS TF Statistics Task Group Leader
Reference Entity Chart Actions If prediction error is: • Outside level 3 limits, run another reference • Outside level 2 limits, reduce calibration period • Outside level 1 limits with pre-determined conditions (such as hardware changes), run another reference • If EWMA (estimate of severity) is: • Outside level 2 limits, run another reference • Outside level 1 limits, apply severity adjustment LTMS TF Statistics Task Group Leader
Industry Difference between current severity estimate and target surveillance panel investigates and pursues resolution Target TMC investigates communicates as appropriate LTMS TF Statistics Task Group Leader
Industry Formulae For the entire industry, • Ti = ith test result in appropriate units • Yi = ith standardized test result where target and standard deviation are as currently defined for the reference oil used in the reference test LTMS TF Statistics Task Group Leader
Industry Formulae (continued) For each severity adjustment entity, • Zi = EWMA LTMS TF Statistics Task Group Leader
Industry Chart Actions • If an EWMA (estimate of severity) is: • Outside level 2 limits, TMC informs the surveillance panel that the limit has been exceeded. The surveillance panel then investigates and pursues resolution of the alarm. • Outside level 1 limits, the TMC investigates whether severity adjustments are adequately addressing the trend, investigates the possible causes, and communicates as appropriate with industry. LTMS TF Statistics Task Group Leader
Annual Review The Technical Guidance Committee (TGC) will organize and conduct annual reviews of the LTMS system in its entirety. Surveillance Panel chairmen are ex officio members of the TGC. The chairmen should prepare with their surveillance panel for these reviews. As part of this preparation, the surveillance panel together with the TMC will review data to determine if any laboratory or laboratories exhibit(s) unusual performance. Such unusual performance might include but will not be limited to severity differences from other laboratories, poor relative precision, high invalid rates, and etcetera. Concerns identified in LTMS data and in the LTMS process should be brought forward to the TGC annual review meetings. LTMS TF Statistics Task Group Leader